WASHINGTON (CN) – Touting the performance of the national electric grid against this winter’s record-breaking bomb-cyclone event, officials assured a Senate committee Tuesday that the independent Federal Energy Regulatory Commission will resist what one senator called “undue political pressure.”

In addition to reflecting on the unusual deep freeze that settled over the Northeast and Midwest last month, this morning’s hearing of the Senate Energy and Natural Resources Committee focused on a recently rejected plan proposed by Energy Secretary Rick Perry to subsidize struggling nuclear and coal power plants.

“It was a transparent attempt in my opinion to prop up the administration’s favorite kinds of energy, which are getting outpaced in the marketplace,” said Sen. Maria Cantwell, a Democrat from Washington state.

While Cantwell applauded the five-member commission for its resistance to bailout pressure, she singled out Commissioner Neil Chatterjee specifically.

The Senate Energy and Natural Resources Committee opens for a hearing on Jan. 23, 2018.

Chatterjee was the temporary chairman of the commission for four months in 2017 before the December swearing in of fellow Trump appointee Kevin McIntyre.

Last week, he disclosed in an ex parte notice that attorney Bill Scherman had lobbied him privately in relation to the agency’s decision to reject the sale of a struggling First Energy coal plant.

Cantwell said she found the communications “troubling … because it said to me that there were those who were trying to influence FERC on a political aspect as opposed to the thorny economic issues that are at stake here.”

“What do you plan to continue to do to make sure that FERC is an independent agency,” she asked McIntyre, using an abbreviation for the commission he now heads.

McIntyre called the agency’s independence “essential.”

“First of all, it’s that way by design, statutorily in its construction, and it’s very important to me personally as I stated here in my confirmation hearing,” he said. “And I intend to do my utmost to ensure that it lives up to that independence.”

Testifying for the first time since his appointment, McIntyre noted that coal and nuclear power accounted for roughly 40 percent of the electricity generated during last month’s freeze.

Power outages this season were minimal in comparison to the polar vortex of 2014, but McIntyre noted that power prices soared to four times their average price as last winter.

“Although we are still receiving and reviewing data, it appears that, notwithstanding stress in several regions, overall the bulk power system performed relatively well,” McIntyre said.

Against McIntyre’s generally positive assessment of the electric grid, another expert warned that vulnerabilities exist in the system that need attention.

Bruce Walker, an assistant secretary at the Department of Energy, testified on Jan. 23 before the Senate Energy and Natural Resources Committee.

Bruce Walker, an assistant secretary at the Department of Energy, said the upcoming retirement of nuclear and coal plants could weaken the reliability of the electric grid that has sustained the United States for more than a century, and which recently helped the Midwest and Northeast weather the deep freeze.

He proposed that the Energy Department conduct an analysis that integrates the resilience-planning efforts by local, state and regional authoroties “into a single North American energy infrastructure model.”

“To address challenges posed by events such as the recent cold snap as well as systemic energy infrastructure issues, it is critical for us to be proactive and cultivate an ecosystem of resilience: a network of producers, distributors, regulators, vendors, and public partners, acting together to strengthen our ability to prepare, respond, and recover,” Walker said.

Resilience requires ongoing and long-term planning, Walker added, noting that it cannot be adequately done just hours or days before an event.

He said the U.S. electric grid needs to be reliable and resilient enough to withstand and reduce, or quickly recover from, power disruptions.